SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f073f2362ae65291fc149926d0c6c5bac8d91400d02cbefb94ec39e9fce59dff' 
  AND token = 'iefx1SIPDddKC79rp6vRZ9YQ31kpfblAYPpKG2ISHPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}